[Решено] Language is not showing on my website (urgent!)

Background of the issue:
I have completed the translation of my website, but it's not showing on the front-end. The default language is Dutch. I also cannot see the WPML switcher in the widget section of Elementor to add it to my navigation header.

Symptoms:
The translated language is not showing on the website, and the WPML switcher is not visible in Elementor.

Questions:
Why is the translation not showing on the front-end of my website?
How can I make the WPML switcher visible in the Elementor widget section?